best coating for gulfcoast area | Roofing Q&A | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

Q&A Forums

Author	Comments
Terry Adams Posted: Feb 12, 2011 12:37 AM	best coating for gulfcoast area Whats the best this cool humid time of the year to coat foam roof.
mason Posted: Feb 12, 2011 07:45 AM	Silicone dries the quickestand doesn't age like acrylic or polyuretheane coatings. But, once you go with silicone you have to stay with it because other coatings won't stick to it. If you are concerned about chemical emissions or need a tougher coating, try the polyurethane coatings. A good moisture cure works well in the humid climates. Acrylic coatings don't typically dry fast in cool humid climates, but there are "fast dry" formulas that can stretch the Acrylics are typically more cost effective than silicone of polyurethane coatings. So as you see any good acrylic, silicone or polyurethane coating will work on the Gulf Coast. Lived there mnore than 30 years right on the coast in Houston then in South Padre Island. and used all of them with great success. The most important thing is to use a coating that has been tested over time in the area. Get one that has very good UV and fungal resistance and keeps its initial physical properties for at least 10 years. Your better coatings can last 15 years before a recoat, some can go up to 20.
Posted: Feb 12, 2011 07:31 PM	Terry, I prefer silicone over acryllic and I am spray foam roofs from Grande Isle, La to Ruston, La. White is extremely white when you first put it on, but dirty's quick. Tan or Beige doesn't seem to get as dirty. Mason's right, once you go silicone, there is no turning back. The only thing that sticks to silicone once you apply is more silicone. Everything else comes off. Steve PS Not sure if you want to make the trip, but I am applying White Silicone as a topcoat tomorrow over SPF, February 13th on a 150 sq roof in Luling,La. Shoot me an email and I will give you directions! We should be there until 3:00 or so
Terry Adams Posted: Feb 12, 2011 08:45 PM	Thanks Mason and Steve, I got myself in a bind by listening to the sales rep. of a large foam manufacturer. Previously used a different supplier and the projects were in the summer time. I let them tell me what I needed and they recommended water-based elastomeric acrylic which I sprayed on per instructions. Started on a Thursday and finished on Friday 1:00PM it was sunny and 70 degrees. 50 hours later it rained (Sunday about 3:00 PM) and washed at least 30% down the gutters. The manufacturer tested the lot numbers @ 72 degrees and 40% humidity and says it dried in 3hrs. They said the best thing to do is wait until the weather warms up and re-coat with same product with multiple thin passes. In other words “tough” its on you. I’ve already replaced them. I plan to prime the washed off areas then thin coat till I get it done unless ya’ll have a better suggestion.
Posted: Feb 14, 2011 10:19 PM	The best thing about silicone in my opinion is that ten minutes after applying, it can get wet and won't run off. Although this is not an ideal situation, you won't have to watch it run off a roof in the rain like an acrylic.
Dennis Davidson Posted: Mar 14, 2011 09:25 AM	I've worked on a lot of roofs in Florida using both acrylics and silicons. Silicone is great but you have to be sure the surface is completely dry or you could end up with coating blisters. It doesn't matter what coating you use as long as you understand the product - and it's limitations! In the case of acrylics, it needs sufficient time to dry between layers. Multiple layers shouldn't be more than 10-12mils (or less) each and spraying should stop by 4:00pm each day. This gives the coating time to start the drying process before the dew hits it in the evening. Once the dew gets on acrylics the drying process stops and doesn't start again until the surface is dry again which might not be till noon the next day. If you apply another layer of acrylic to soon then your trapping moisture and so takes twice as long to cure. We have a problem with cool temps in the North. The cooler it is the longer it takes for acrylics to dry. The other thing to look at is the solid by volume content. In most cases, the higher the solids the faster it drys so if you use a "cheap" acrylic you'll most likely have to make up for it in extra labor cost on a third or even forth coat

Author

Comments

Terry Adams

Posted: Feb 12, 2011 12:37 AM

best coating for gulfcoast area

Whats the best this cool humid time of the year to coat foam roof.

mason

Posted: Feb 12, 2011 07:45 AM

Silicone dries the quickestand doesn't age like acrylic or polyuretheane coatings. But, once you go with silicone you have to stay with it because other coatings won't stick to it. If you are concerned about chemical emissions or need a tougher coating, try the polyurethane coatings. A good moisture cure works well in the humid climates.

Acrylic coatings don't typically dry fast in cool humid climates, but there are "fast dry" formulas that can stretch the Acrylics are typically more cost effective than silicone of polyurethane coatings.

So as you see any good acrylic, silicone or polyurethane coating will work on the Gulf Coast. Lived there mnore than 30 years right on the coast in Houston then in South Padre Island.
and used all of them with great success. The most important thing is to use a coating that has been tested over time in the area. Get one that has very good UV and fungal resistance
and keeps its initial physical properties for at least 10 years. Your better coatings can last 15 years before a recoat, some can go up to 20.

Posted: Feb 12, 2011 07:31 PM

Terry, I prefer silicone over acryllic and I am spray foam roofs from Grande Isle, La to Ruston, La. White is extremely white when you first put it on, but dirty's quick.

Tan or Beige doesn't seem to get as dirty.

Mason's right, once you go silicone, there is no turning back. The only thing that sticks to silicone once you apply is more silicone. Everything else comes off.

Steve

PS Not sure if you want to make the trip, but I am applying White Silicone as a topcoat tomorrow over SPF, February 13th on a 150 sq roof in Luling,La. Shoot me an email and I will give you directions! We should be there until 3:00 or so

Terry Adams

Posted: Feb 12, 2011 08:45 PM

Thanks Mason and Steve,
I got myself in a bind by listening to the sales rep. of a large foam manufacturer. Previously used a different supplier and the projects were in the summer time. I let them tell me what I needed and they recommended water-based elastomeric acrylic which I sprayed on per instructions. Started on a Thursday and finished on Friday 1:00PM it was sunny and 70 degrees. 50 hours later it rained (Sunday about 3:00 PM) and washed at least 30% down the gutters. The manufacturer tested the lot numbers @ 72 degrees and 40% humidity and says it dried in 3hrs. They said the best thing to do is wait until the weather warms up and re-coat with same product with multiple thin passes. In other words “tough” its on you. I’ve already replaced them. I plan to prime the washed off areas then thin coat till I get it done unless ya’ll have a better suggestion.

Posted: Feb 14, 2011 10:19 PM

The best thing about silicone in my opinion is that ten minutes after applying, it can get wet and won't run off.

Although this is not an ideal situation, you won't have to watch it run off a roof in the rain like an acrylic.

Dennis Davidson

Posted: Mar 14, 2011 09:25 AM

I've worked on a lot of roofs in Florida using both acrylics and silicons. Silicone is great but you have to be sure the surface is completely dry or you could end up with coating blisters. It doesn't matter what coating you use as long as you understand the product - and it's limitations! In the case of acrylics, it needs sufficient time to dry between layers. Multiple layers shouldn't be more than 10-12mils (or less) each and spraying should stop by 4:00pm each day. This gives the coating time to start the drying process before the dew hits it in the evening. Once the dew gets on acrylics the drying process stops and doesn't start again until the surface is dry again which might not be till noon the next day. If you apply another layer of acrylic to soon then your trapping moisture and so takes twice as long to cure. We have a problem with cool temps in the North. The cooler it is the longer it takes for acrylics to dry. The other thing to look at is the solid by volume content. In most cases, the higher the solids the faster it drys so if you use a "cheap" acrylic you'll most likely have to make up for it in extra labor cost on a third or even forth coat

You need to login to reply to this topic. Please click here to login.